Step1 Inventory your home to see how energy-efficient it currently is. That means checking to see how much insulation is in the attic, walls and crawl spaces, checking for drafty windows or doorjambs and patrolling the outside of your home to look for broken window panes.

Step2 Determine whether there are at least 6 inches of insulating fiber in your attic or crawl space. Anything less than 6 inches won't be effective in combating drafts and keeping the temperature of your home constant. You can purchase insulation at your local hardware store (if necessary) and add more--making sure to distribute it evenly throughout the space.

Step3 Check to see if the walls of your home are insulated. Surprisingly, many older homes have little to no insulation between the studs and the wallboard, creating a significant loss of heat and energy. Speak with a contractor or knowledgeable friend about how complicated a job it would be to insulate the walls before you attempt to do it yourself.

Step4 Apply weather-stripping around drafty doorjambs and windowsills. Weather stripping can be purchased at most major retail stores and comes in vinyl, spring metal or adhesive-backed varieties. Check the back of the package to see what types of doors are most compatible with the type of material, keeping in mind that you may need to purchase a combination of weatherstripping materials to weatherize all the doors and windows in your home.

Step5 Use foam sealant or caulking to fill in gaps around the ceilings and floors and other cracks in the walls of your home. It's best to use an expanding foam sealant on the larger cracks that won't be exposed to sun or moisture, while caulk works better on smaller gaps and cracks, such as those around electrical plates and switches.

Step6 Install storm windows in homes with older model windows. Many newer homes have single-hung windows which are more energy-efficient and don't require the extra protection of storm windows. Both types of windows, however, would benefit from the use of plastic-film storm window kits. With these kits, the plastic is taped to the window and then shrunk with a hair dryer to create a tight seal around the window. They're relatively inexpensive and are readily available for purchase at many hardware stores.

Step7 Hang heavier curtains in the rooms in which you spend a lot of time. Though you may not get as much sunlight as you wish, the heavy material will help to absorb some of the cold air that seeps in through the window.